There are lots of new products popping ,Hybrids & diy coatings. Many probably don't block the paint as bad as the full on professional coatings, but I'm remaining on the skeptics list, ESPECIALLY with anything other than a paper thin factory paint job. I'd prefer to not even do carnuba on a showcar thickness paint any less than over a year later for fear of solvent trap. Sand into a quality paint job 10 to 20 years later & it still has some fresh paint smell.
Many of these coatings advertise higher gloss levels, but anyone that knows their a$$ from a hole in the ground knows they need paint correction first, which is where most of the added gloss comes from.